Inclosed fuse.



5"; A. SCH/11111, 41111110510 FUSE. APPLicATloN FILED APR. 23.1914.

Patented May15,1917.'

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7l]IIlIlllllllll/llIl/lll EY/vena? @@Ofyz. 60721167067" ITED e TAES PATENT OFFICE.

GEORGE A. SCI-IAEFER, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO FRED W. IRVING, OF CHICAGO, ILLINOIS.

INCLOSED FUSE.

Specification of Letters Paten-t.

Paten-tea May 15, 1917.

' To all whom t may concern.

' terminals 4of the fuse without the use of special tools. The parts are of simple con'- struction, and the operation of assembling a new fuse link in the fuse tube between the terminals or' the juse is readily accomplished without the exercise oit special skill.

The several drawings illustrating my invention are as follows:

Figure l shows in perspective the various parte of my device in its disassembled condition;

Fig. 2 shows in longitudinal sectional view one end of my fuse;

' Fig. 3 shows anoutside view of my fuse completely assembled;

Fig. d' shows in a view to a somewhat smaller scale a longitudinal section similar to Fig. 2, a fuse completely assembled.

Similar numerals refer to similar parts vthroughout the several views.

shown in Figs. 'l and 2. the Jfuse con-- sists of t tubular shell 1, of insulating material, preferably hard liber, threaded eX- ternally at either end and provided ntf i either end with opposite keyways 2. 'The connectorat each end of the fuse is composed of a pair of contact plates 3 and et, each of whichis bent at substantially right angles so that the outwardly extending part 3a or 4 constitutes one ot the surfaces for engaging the connector with which the fuse is to be. used, while the other part 3b and@b forms a portion of the end wall of the fuse 2. The parts 3') and 4b are semicircular in `t'orm, so that they together li'orm a-`disk .somewhat larger than the bore of the tube l, and somewhat smaller than the outside diameter of said tube so that the internally threaded sleeve 5 may pass freely over the disk thus formed to engage the threads formed on the end of the Atube l. The portions 3 and l have lateral keys 6, extending from their inner surfaces to engage the keyways 2, so Athat the contact plates 3a and sa at one end of the fuse may be held substantially in alinement with the similar contact plates at the other end of said fuse. The disk portions 3b and 1b are provided with vent holes 7 as may be necessary for properly releasing the pressure in the tube l, caused by the gases resulting from the blowing of a fuse link,

rlhe disk portions 3b and all have their edges slightly beveled, as indicated at 7 and 8, to engage the similarly beveled inner surface 9 of the end of the sleeve 5. rlhe end of the sleeve projects inward beyond the beveled surface 9 only a sufiicient distance to positively engage the disk portions 3b and lb when the sleeve is screwed onto the tube sufliciently to bring the entire beveled surface 9 into engagement with the outer edge of the disk portions 3* and 4b, which may occur when comparatively thin fuse links are used. As a result of the construction described, when it is desired to mount one of the fuse links 10 in the shell, the sleeve 5 is entirely removed from one end of the shell, and the other slee've is sulficiently loosened to release the contact plates 3a and 4a of the correspond-ing terminal. The remaining parts of the old fusemay th-en readily be removed. Assuming that an absorbent filling material 1l of asbestos,` sand, or any other desired substance has been employed, this material is then removed from thetube, and a new fuse link is readily slid into place through the loosened contactyplates Stand 4a. These links are suiciently long to extend from the outer end ofA one terminalto the outer end of the other-terminal. of the fuse and may be preferably of uniform .thickness throughout, so that they may conveniently be made from sheet fusible metal without the addih tion of any terminals of any kind. One or more holes l0 are preferably provided near the middle portion of the fuse link todetermine the point at which the uselink will blow. The fuse link thus inserted between the loosened contact plates projects suiliciently beyond the other end of the tube l, so that the other pair of contact plates may be located in proper position upon either side of it, as indicated in Fig. 4, with the keys of the contact plates engaging the keyways in the tube. Before this Vis done, iii' an absorbent filler is to be used it is, of course, packed in place around the fuse link. The remaining sleeve 5 is then passed over the contact plates last named and screwed onto the end of the tube l, until the inner beveled surface of said sleeve firmly engages the outer beveled edge ot said contact plates. As a result ot the beveled edges reierred to, the Contact plates are iorced irmly together and also against thc end ot the tube l, so that the fuse link is held securely between the contact plates. rllhe sleeve 5 at the other end oll the tube is then. screwed firmly into engagement with its pair oil" contact plates and the t'use link is similarly clamped at that end. rThe fuse is then ready for insertion into the coni'iectors l2 and 13, which are preferably ot the jaw type, as indicated in Fig. 3. The pressure oif the contact jaws of the connectors is eii'ective in holding the contact plates o'l' the 'luse firmly in engagement with the i'use link so that i'or all. operating conditions, the fuse link is held in good electrical contact with the terminals of the t'use, in the saine manner as thoughv special clamping devices i'or permanently attaching the iuse link to the l'use terminals were employed.

lVhil'e I have in my construction, as above described, employed beveled sui-'tacos tor exerting a clamping action upon the fused link, by means of the 'fuse terminals it will be understood that this is not necessary, although it is a preferable construction, tor without these l'icvcled surfaces the clamping plates at either end of the luse are held se curely in position against the end ot the fuse tube, and the pressure exerted by the jaws otl the connectors holds the contact plates securely in engagement with the fuse link during its operation.

My improved iuse construction is equally applicable to incloscd fuses used without absorbent illing material, and similar fuses employing any desired kind. of absorbent filler.

While I have shown my invention in the `particular embodiment herein` described, it

will be understood that I do not limit myself to this exact construction as I may employ any equivalent thereof without departing from the spirit of my invention.

What I claim is:

1. In an inclosed fuse, the combination of a tube, a pair of plates associated with one end of said tube and each having a portion extending outwardly to constitute a part of the end wall oi the tube, a fuse lint. having its end between said contact plates, and a sleeve carried by the end of the tube for holding the contact plates in position upon either side o't' said fuse link, said sleeve and said outwardly extending portion having cooperating beveled surfaces for exerting a clamping e'llfect upon said fuseV link.

2. In an inclosed fuse, the combination of an insulating tube, a pair of angular clamping plates at each end ot .said tube, coperating keys and keyways carried by the tube and clamping plates tor alining them, a flat fuse link extending through said tube and between theclarnping plates at either end thereof, and a threaded. sleeve carried by each end ot' the tube 'for holding the corresponding clamping plates in position upon opposite sides ot said 'fuse link, the outwardly extending portions ot said clamping plates beingl circular and. beveled and en .gaging similar internal beveled surfaces carried by said sleeves.

4In an inclosed tuse, the combination of an insulating tube, a closure ior each end of said tube, comprising a pair of integral bent plates, each having a hmgitudinally eX- teuding contact portion and a laterally eX- tending sen'iicircular portion, a flat inse link extending between the longitudinal extensions ot the cud closures, and a threaded sleeve mounted upon each end of said tube l'or holdingI said closures securely in contact with said tube, said closures having beveled edges cooperating with similar internal beveled suriaces upon said sleeves to clamp said longitudinal extensions against said 'fuse link. i

4, In an inclosed iuse, the combination of an insulating` tube, threaded sleeves on the ends ot the tube, scioii-ircnlar end closures separate iii-oni said sleeves and held in position thereby to close the ends ot said tube, said end closures being of rigid metal each having a contact blade extending rigidly therefrom axially ot the tube, said tube having kcywavs and said end closures havingI keys cooperating therewith to prevent rotation ot said end closures relatively to said tube without intel-tering with the seating of said end closures against the ends of the tube, and a flat fuse link extending through said tube and between said blades, whereby the insertion ot said blades into connecting jaws clamps the ends of said fuse link between said blades.-

5. lin an inelosed fuse, the combination of an. insulating tube, threaded sleeves on the ends of the tube, a pair of rigid semi-circu lar metal plates separate from the corresponding sleeve and held in place thereby to close each end ot said tube, said plates having rigid integral bla des extending outwardly in parallel relation with the axis of the tube, said tube having keyways and said plates having keys coperating therewith te prevent of said fusi;J link when said blades are inrotation of said plates relatively to Said tube Serted in a Connector jaw. 10

without interfering with the seating of said In Witness whereof, I hereunt subscribe plates against the ends of the tube, and al my name this 15 day of April, A. D. 1914.

f Hat fuse link extending through the tube and GEORGE A. SCHAEFER.

' between the blades substantially from end Witnesses:

to end of vsaid blades, whereby each pair of FRED W. IRVING,

bla-des firmly clamps the Corresponding end HARRY R. FOSTER,-

Gopies of this patent inay be obtained for five cents each, by addressing the Commissioner of. laten'llnl,v Washington, D. C. 

